etl-launcher attempts to find manual data installed using original ET
for Linux archive.

etlegacy-linux-assets-installer extracts data directly to home
directory, where etlegacy can find them without additional changes.
Enables also installation of data for all users on the machine. Can run
nicer prompts using dialog script.

Installer would prepare all symlinks in sudo mode, etl-launcher should
not be necessary after it. Include also data instruction HTML.

It now produces versions with architecture suffix appended. Pass suffix
as the first parameter to laucher. Shared one laucher for potentially
multiple architectures.